I'd like to close the loop by explaining the source of my misunderstanding, in case someone else has the same issue:
I was confusing cash with available funds. The maintenance margin applies to the available funds, not cash. I can indeed use all my cash balance to buy securities.
Thanks, I'll do that, the confusion is also due to the fact that my cash amount did go down the full 40k (not just 10k as you said), but then I also had the 10k initial margin.
I think I may be misunderstanding something. I thought that to keep the maintenance margin I had to actually have the unused cash balance in my account, but instead it seems that I can use my full cash balance to buy an equity (stock A), as long as the value of the equity (stock A) remains above...
One thing that bothers me though, is I invest 40k of cash into some position, now I have a margin maintenance of 10k in my account, which means I need to keep 10k of cash sitting in my account doing nothing so I could sustain a potential margin load that I don't need. Is that correct?
So, this all happened 2 days ago, meanwhile I deposited another 50k but the margin has not gone back to 0. I will wait a few more days and see what happens.
I have a question about why I have an initial and maintenance numbers on my IB account.
Here's what I did
1) Converted 10k EUROS to USD using idealpro.
2) Bought 9k USD worth of ETF in a single transaction.
Now my account has 2250 initial margin and maintenance margin.
Is this because the...